LLC种植瘤靶向USPIO标记间充质干细胞MRI活体示踪试验

Experimental Study on LLC Implanted Tumor Targeting USPIO Labeled Mesenchymal Stem Cells by MRI in Vivo

将超顺磁性氧化铁微粒-多聚赖氨酸(USPIO-PLL)标记的人脐带间充质干细胞(HUMSCs)移植入小鼠Lewis肺癌细胞(LLC)种植瘤模型小鼠,利用3.0TMR对HUMSCs的活体示踪技术,观察移植小鼠体内的HUMSCs磁共振(MRI)信号及肿块大小的变化,探讨HUMSCs移植肺癌动物模型后的定向迁移、转化情况及间充质干细胞(MSCs)对肿瘤的影响。以PLL为转染剂,用USPIO对HUMSCs-PLL进行磁性标记;将磁标记的HUMSCs通过鼠尾静脉移植入Lewis肺瘤细胞(LLC)种植瘤小鼠体内,分别于移植前、移植后1d、10d进行MRI观察。结果显示,USPIO-PLL可安全有效标记HUMSCs,标记率大于96%,细胞活性达标。移植后1dMRI可监测到HUMSCs到达肿瘤区,10d到达肿瘤区MSCs增多,MRI信号显著降低(P<0.05)。建模成功后,各试验组移植后1d和10d肿瘤体积差异不显著(P>0.05);移植后1d和10d抑瘤率均为正值。说明3.0T MRI可以有效进行标记干细胞移植后的活体示踪。HUMSCs对LLC种植瘤有定向趋化作用,可以聚集至肿瘤区域发挥抑瘤作用,又可促进肿瘤血管生成,多种影响相互交叉最终抑制肿瘤生长。

In this study, human umbilical cord mesenchymal stem cells （HUMSCs） labeled with ultra-superparamagnetic iron oxide microparticle-polylysine （PLL） were transplanted into lung cancer LLC mice, and the HUMSCs were expressed by a.0TMR.MRI signal and tumor size in transplanted mice were oh- served to investigate the directional migration and transformation of HUMSCs transplanted lung cancer and the effect of HUMSCs on the tumor. HUMSCs-PLL was magnetically labeled with USPIO. Magnetic marker HUMSCs through rat caudal vein transplantation into the LLC growing tumor mice.MRI was observed before transplantation,ld and 10d after transplantation.Results. HUUSPIO-PLL could safely and effectively label umbilical cord mesenchymal stem cells with a labeling rate more than 96% and cell viability reaching the standard; 1 day after transplantation,the mesenchymal stem cells reached the tumor area, There were more MSCs reached the tumor area at 10 days after transplantation,the difference was statisti- cally significant （P〈0.05）.There was no significant difference in the tumor volume between the experimental group and the 10 days after transplantation （P〉0.05）.The tumor inhibition rate was positive at 1 day and 10 days after transplantation. So, 3.0T MRI can be used for stem cell transplantation in vivo; HUMSCs on LLC implantation have a directional chemotactic effect, can be gathered to the tumor area, and play an anti-tumor effect; but also promote tumor angiogenesis; multiple effects cross each other to ultimately inhibit the tumor growth.